BAL HARBOUR, FLA. – Cognition declines in the years after a single stroke for a substantial minority of patients, according to a study presented at the annual meeting of the American Neuropsychiatric Association.
After the initial poststroke period, most experts would expect cognition to improve or remain static, according to the literature. However, some studies with a longer follow-up now suggest cognitive decline is possible after a single stroke, even in younger patients. The current research supports that finding and shows the utility of screening patients with the Mini Mental State Examination (MMSE).
The cognitive impairment due to stroke is not static. “Our findings suggest there is a subpopulation that continues to decline as they age,” Gregory Kellermeyer, M.D., said in an interview.
The investigators assessed 16 men and 10 women at least 1 year following a single known stroke. The mean follow-up was almost 6 years. Participants were relatively young with a mean age of 58 years. Pretreatment data for the stroke survivors came from a study of constraint-induced movement therapy for upper extremity motor impairment. Cognitive deficits can occur independent of motor decline. The implication is that “even a single stroke may in some persons incite a progressive neurodegenerative process that preferentially affects cognition,” the investigators wrote.
There was possible cognitive impairment in 6 of 27 participants (22%) and definite cognitive impairment in 2 of 27 (7%). Possible cognitive impairment was defined as a greater than 1 standard deviation on the adjusted MMSE; definite cognitive impairment was defined as greater than 2 standard deviations. “The Mini Mental State Examination is a possible way to identify this subpopulation,” said Dr. Kellermeyer, a fourth-year resident in psychiatry at the University of Colorado, Denver.
Patient age alone, gender, handedness, stroke laterality, and severity of motor impairments were not significantly associated with raw or adjusted MMSE results. These MMSE scores were inversely related to time since the stroke.